Coming together at the special bench dedicated to their childhood pal, the school friends posed for pictures with their red balloons to raise awareness for the charity's campaign.

Catherine Buchanan

School friend Emma Murphy, who was chosen to front this part of the campaign for the blood cancer charity, spoke to Belfast Live about her friend and the pain of losing her.

"Catherine and I met when we were seven, we met in primary school. We were really good friends the whole way through school," said Emma, who is now 19.

"It was such a shock when we lost her, she had been in our lives for so long. Catherine was just 17 when she was diagnosed, it was very sudden. We found out like a week before she died she had a rare form of leukaemia.

"She went into hospital and they did not know what it was, she had flu symptoms. Within a week she had died. We had just started upper sixth in September 2013. She was there for the first day of school, maybe the first week but within the second week she was off from then.

"She missed so many experiences in sixth form, the formal and everything, we did not get to have her there."

But in a sign of how well thought of she was at Strathearn, the year group came together to dedicate their formal to Catherine with part of the formal money going to charity.

"We sold red bands too, it was good at bringing the year together and having something for her," said Emma, who is studying primary school teaching at Stranmillis.

"It was tough but the year became closer, everyone was remembering her together."

Catherine, who had a passion for horse riding and wanted to become a scientist, died so quickly after being diagnosed it shook all of her nearest and dearest to the core.

"It was so sudden," said Emma.

"We had no time to process the fact she had leukaemia never mind what would happen. It took a long time for us to process the whole thing."

Emma Murphy pictured as part of the 99RedBalloons campaign

Catherine's parents, who have raised thousands for Leukaemia & Lymphoma NI since losing their daughter, bought a bench dedicated to her for the grounds of her school Strathearn.

Emma said it was nice for her friends to come together at the bench to remember Catherine and do something positive in her memory.

"It was nice to go back as a friendship group, we had seen the bench before but it was nice to have us all together, all of Catherine's closest friends from school" she said.

"We are all very close as a friendship group, but there were some who could not make it."

Emma said she and her other friends have been working closely with the charity alongside Catherine's parents. A ball was held earlier this year in memory of Catherine for the charity.

"It's been two years but it still hits you, I think about her all the time," said Emma, from East Belfast.

"Catherine had a real passion for horse riding and all through primary school when I was talking to her, we would talk about horses.

"She was also really academic, she was the smartest person I knew. It is awful because she would have gone on to do amazing things.

"She was so chatty and loved laughing, she would laugh at anything and she had the best laugh ever. She would just go off crying with laughter. She was just like any of us really, she was a really nice person.

"We all talk about her quite a lot, she was such a big part of our lives. We do not want to forget her, we do not want her memory to be forgotten and all the fun times we had together.

"Her mum and dad will email us all quite regularly to let us know if anything is going on and it's nice to see them. I think it is nice for them to know what we are doing because we were all so close before."

Speaking about the campaign, Emma added: "It was just really trying to bring a positive thing out of the situation. We can raise awareness and more people will donate then hopefully we will find a cure.

"It is not something I want people to go through, if we can create something positive out of her memory then that's great."

Ninety-nine people are diagnosed with a blood cancer such as leukaemia, lymphoma or myeloma every month in Northern Ireland.

Caroline Crothers, a coordinator with Leukaemia & Lymphoma NI, said the campaign, which is in its eighth month, has seen different people affected by blood cancer front 99RedBalloons each month.

"This month was especially special to us because Catherine Buchanan lost her life two years ago this month," she said.

"It was very sudden and her family have been big supporters of us. Catherine would have been going into her second year at university and we thought it would be good to get her friends together before they go back and the bench was donated to the school.

"It was really nice for her parents to see her friends together for the photoshoot.

"We are asking people not to just engage with the campaign but to donate too. We also plan to make a calendar from the pictures for 2016.

"September is blood cancer awareness month and the thing with blood cancer is a lot of the symptoms people would recognise like fatigue and recurring infections and night sweats but they are things which at some point we all get.

"Blood cancer can get missed or it takes longer to be diagnosed so we would like people to be more aware. If they are suffering night sweats or more tiredness than usual or a recurring throat infection, then go and see your GP."